/Engine/Source/Runtime/Engine/Public/ISubmixBufferListener.h
Called when a new buffer has been rendered for a given submix
void OnNewSubmixBuffer ( const [USoundSubmix](API\Runtime\Engine\Sound\USoundSubmix) * OwningSubmix, float * AudioData, int32 NumSamples, int32 NumChannels, const int32 SampleRate, double AudioClock )